EP0281157B1 - Energieversorgung für einen induktiv gekoppelten Plasmabrenner - Google Patents

Energieversorgung für einen induktiv gekoppelten Plasmabrenner Download PDF

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Publication number
EP0281157B1
EP0281157B1 EP88103403A EP88103403A EP0281157B1 EP 0281157 B1 EP0281157 B1 EP 0281157B1 EP 88103403 A EP88103403 A EP 88103403A EP 88103403 A EP88103403 A EP 88103403A EP 0281157 B1 EP0281157 B1 EP 0281157B1
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EP
European Patent Office
Prior art keywords
plasma
power
radio frequency
induction
torch
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EP88103403A
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English (en)
French (fr)
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EP0281157A2 (de
EP0281157A3 (en
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Peter J. Morrisroe
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Applied Biosystems Inc
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Perkin Elmer Corp
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/30—Plasma torches using applied electromagnetic fields, e.g. high frequency or microwave energy
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • H05H1/34—Details, e.g. electrodes, nozzles
    • H05H1/36—Circuit arrangements

Definitions

  • the present invention relates generally to the field of inductively coupled plasma torches and more particularly to a plasma torch and an associated power supply system for improved operation of the plasma.
  • ICP inductively coupled plasma
  • the gases necessary to sustain an ICP discharge are commonly introduced into a torch constructed of a quartz tube which partially contains the high temperature plasma.
  • the tube surrounds the discharge to shape the plasma which is maintained by the radio frequency field created by the induction coil encircling the quartz tube.
  • US-A- Re. 29,304 and US-A-4,266,113 illustrate typical ICP torches that may be used for spectroscopy, comprising three concentric tubes.
  • the plasma-forming gas is passed through the annular space between the innermost tube and the middle tube.
  • the innermost tube, or pipe terminates near the plasma region and is used for a carrier gas containing the sample substance being injected into the plasma.
  • a cooling gas for the tube assembly which may be the same type or a different gas than for the plasma, flows between the outermost tube and the middle tube.
  • the induction coil is typically formed of copper tubing and is generally water cooled.
  • the torch assembly is fixed with respect to the induction coil so that the sample substance is injected axially near the rear end of the coil; i.e., the lower end of the coil in a vertical configuration with the plasma issuing upwards.
  • US-A-4,578,560 discloses the use of flanges on the bottom ends of the tubes which connect to corresponding flanges of lower mounts. Spaces are placed between the connecting flanges to provide adjustment of the tubes during assembly, fixing the positions for operation.
  • US-A-3,324,334 mentions a high energy spark source (at column 5, line 46) but provides no details.
  • a tap from the radio frequency generator is disclosed (Fig. 2 of the referenced patent), but in practice this has not been very reliable for starting.
  • US-A-4,482,246 teaches the use of a Tesla coil which is relatively expensive.
  • a lower cost device is disclosed in aforementioned US-A- Re. 29,304 whereby a carbon rod is introduced into the open end of the torch where it is heated by the radio frequency field, in turn heating the gas to initiate the plasma (column 5, lines 15-20); however, this device also has proven to be unreliable.
  • a typical circuit is shown in the Re. 29,304 patent (Fig. 2).
  • the main oscillator is a "tank" circuit, i.e., an LC circuit, in combination with a vacuum triode tube having a DC power supply on the plate.
  • a second LC circuit includes the induction coil for the ICP, that coil also providing at least part of the inductance for the second LC circuit. Coupling between the circuits is either inductive or capacitive. The two circuits are tuned to similar frequencies to obtain transfer of power.
  • US-A-4,629,940 shows the utilization of variable capacitance for retuning in which the retuning is done automatically through feedback circuitry. Although such a system has been quite successful, it generally is cumbersome, expensive, and prone to malfunction.
  • the ICP to be distinguished from a different type of radio frequency plasma generator as disclosed, for example, in US-A-3,648,015, in which the plasma is generated capacitively.
  • a metallic nozzle assembly is attached to the output coil and the plasma is generated from the tip of the nozzle.
  • the plasma-forming gas is provided to the nozzle through its connection to the coil which is formed of piping. The gas and a powder are introduced into the coil pipe at another connection point.
  • a radio frequency exciter apparatus for an inductively coupled plasma generating system is known from EP-A1-0122403.
  • a radio frequency generator mechanism of a selected radio frequency comprises an LC network to which a work coil is coupled via an impedance matching capacitor connected in series with the work coil.
  • a primary object of the present invention is to provide an improved induction plasma generating system that remains stable over a range of operating conditions.
  • Another object is to provide a novel induction plasma generating system having a precisely regulated power output.
  • a further object is to provide an improved induction plasma generating system having a constant power output over a range of operating conditions.
  • Yet another object is to provide an improved power regulation system capable of fast response in maintaining constant voltage as load conditions vary.
  • the system includes means for maintaining constant power to the plasma discharge.
  • Such means comprises a radio frequency generator including the output LC network and the oscillator network that includes a power triode with a plate and being coupled to the output LC network.
  • a DC power supply for effecting a rectified voltage to the triode plate includes an input transformer with a primary winding receptive of AC power.
  • An AC circuit receptive of line voltage for effecting the AC power includes means for duty cycling the AC power in response to a control signal, feedback means for generating a feedback signal relative to the rectified voltage, and control means receptive of the feedback signal for producing the control signal such that a change in the rectified voltage effects an inverse change in the duty cycling such as to nullify the change in the rectified voltage.
  • a tubular torch member 12 is formed of quartz or other electrically insulating material.
  • a helical induction coil 14 having about three and one half turns is shaped from copper tubing and encircles the upper part of the torch member generally concentrically therewith.
  • a small diameter pipe 16 of similar material or preferably alumina is positioned along the axis of the torch, terminating in the vicinity of coil 14 as will be described in detail below.
  • a tubular intermediate member 18 preferably of the same composition as the torch member, is located concentrically between torch member 12 and pipe 16 , forming an inner annular space 20 outside pipe 16 and a second relatively thin outer annular space 22 inside torch member 12 . Intermediate member 18 terminates at about the rearward edge of coil 14 .
  • Torch member 12 , intermediate member 18 and pipe 16 are affixed concentrically with respect to each other in a mounting member 24 with O-rings 26 .
  • a first conduit 38 for conveying plasma-forming gas from a source 40 into inner annular space 20 , by way of the piping of coil 14 is connected to the lower part of intermediate member 18 and extends laterally therefrom.
  • the plasma-forming gas thus flows in a forward direction with respect to torch 10 ; i.e., upwardly in the orientation shown in the present example.
  • a second conduit 42 for cooling gas from a source 44 is similarly connected to torch member 12 .
  • the sources 40 , 42 optionally may be the same single source.
  • the plasma-forming gas is preferably argon but may be any other desired gas such as nitrogen, helium, hydrogen, oxygen, hydrocarbon, air, or the like.
  • the bottom end of the central pipe 16 protrudes downwardly through mounting member 24 and is attached through a third conduit 46 to a source of carrier gas 48 .
  • a sample of substance from a sample container 50 to be introduced into the plasma is fed into the carrier gas flow through a valve 52 from a source of the sample or material, in liquid or powder form. Such substance may be for spectrographic analysis or other treatment by the plasma as desired.
  • the carrier gas itself may be the sample.
  • the fluidized sample is thus conveyed upwardly (forwardly) through an orifice 54 in pipe 16 and injected into a plasma region 55 generated within induction coil 14 and torch member 12 .
  • Mounting member 24 is slidingly retained in a torch body 56 such that the mounting member and its assembly 58 of torch member 12 , intermediate member 18 and pipe 16 can be moved vertically.
  • An upper shoulder 60 and a lower shoulder 62 are provided in torch body 56 to engage respective upper and lower end surfaces 64,66 of mounting member 24 to position the mounting member in an upper (forward) position or lower (rearward) position respectively; the lower position of mounting member 24 is shown in Fig. 1.
  • a vertical slot 57 in torch body 56 accommodates movement of the gas conduits 38,42 .
  • a vertical strut 68 is attached to a side 70 of mounting member 24 and extends down beyond torch body 56 .
  • a set of teeth 72 arranged vertically is cut into the strut 68 to form a rack.
  • a pinion gear 74 engaging teeth 72 is mounted on a shaft 76 to which a control knob 78 also is mounted.
  • motor, pulley belt or the like causes strut 68 , mounting member 24 and tube assembly 58 to move vertically between the shoulder limits 60 , 62 .
  • Mounting member 24 may be moved by any other desired means, such as a stepper motor.
  • More reliable ignition of a stable, properly-formed plasma discharge is obtained by vertical position adjustability of the quartz torch. Proper aerodynamic flow at the load coil location is assured so that destructive ring discharges are unable to form during ignition. The adjustment then locates the injector tip at, or close to, the lower location where the plasma forms, which greatly simplifies formation of a sample channel axially through the plasma, and when the sample is subsequently injected it is restricted from circumventing the plasma region.
  • Induction coil 14 is retained on a tubular mount 80 formed of a cylindrical section 82 on which the coil is positioned snugly.
  • Tubular mount 80 has an axial length that is enough greater than that of coil 14 so as to extend the mount to a contact surface 86 on torch body 56 to position coil 14 with respect to body 56 .
  • the tubular mount also has an upper flange 90 extending radially outwardly from cylindrical section 82 at the top (forward end) thereof.
  • the upper flange has an outer diameter greater than the outer diameter of coil 14 and is adjacent to the forward edge 92 of the coil, so as to provide a radio frequency barrier between the coil and the open end of the torch.
  • Coil 14 is positioned vertically between upper flange 90 and a lower flange 91 .
  • an electrically conductive probe 94 is extended through a slot 96 in the forward end of the torch member 12 .
  • the probe is electrically connected to the high voltage output of a piezoelectric crystal 98 capable of yielding a pulse of at least 10 kilovolts, for example about 20 kilovolts.
  • a pneumatic piston assembly 100 is supplied by a source 102 of compressed gas through a valve 104 and is connected mechanically to the crystal by a rod 106 .
  • a mechanical pulse from the rod to the crystal results in a very high voltage pulse that triggers a spark from the tip 108 of probe 94 at the torch.
  • the plasma is initiated by first applying the radio frequency power to the induction coil and then pulsing the crystal. Pulsing may be repeated as necessary at a higher repetition time than the full recovery cycle time of the piezoelectric crystal, allowing creation of sufficient ionized gas intermittently to cause ignition as if a continuously ionized stream was being produced. Starting the plasma discharge in this manner has been found to be highly reliable and the piezoelectric crystal system has a relatively low cost compared to prior reliable starters.
  • the plasma discharge is thus formed in the torch member in plasma region generally within the induction coil.
  • the injector pipe, and preferably the entire torch assembly is adjusted axially with respect to the induction coil while the plasma discharge is energized.
  • Such position of the pipe is shown by broken lines 114 in Fig. 1.
  • the injector tip is withdrawn to a second position, which is that shown in the figure, proximate a second plane 116 that is oriented perpendicularly to the axis of the coil in contact with the rearward edge 118 of the coil.
  • the radio frequency (RF) system 200 is a 40 MHZ tuned power oscillator, capacitively coupled to a high Q tuned output network which powers the inductively coupled plasma.
  • the frequency generally should be between about 20 MHZ and 90 MHZ, preferably between 30 MHZ and 50 MHZ, for example 40 MHZ.
  • An oscillator network 202 comprises a power triode amplifier 203 with a filament circuit 204 , a feedback and grid leak biasing circuit of inductance Lf, capacitance Cf and resistance Rb, and a tuned plate circuit coil Lp and capacitance Cp.
  • the output of oscillator 204 is capacitively coupled through Cc to the output network 204 comprising capacitance CL; such capacitive coupling Cc is preferable over inductive coupling due to lower impedance and undesirable effects of heating.
  • Output network load coil 14 is used to inductively couple the RF power to the plasma.
  • Coil Lp is conventionally formed of metal sheet which also intrinsically provides the capacitance Cp.
  • the coupling capacitor Cc between the oscillator and the output network is also formed of metal sheet proximate Lp/Cc, shown schematically in Fig. 2 as a tap coming off of coil LP.
  • a tunable capacitor Cl is used to tune the circuit and comprises a third metal sheet variable in position. Once this is adjusted upon assembly of the system it need not be changed again.
  • a capacitance Cs is stray capacitance formed by the proximity of the output network to its enclosure, and is the RF return for load coil 14 .
  • output LC network 206 is tuned without sample injection to a higher frequency than oscillator network 202 , thereby allowing only a predetermined fraction of the oscillator power to be coupled through Cc to the output network and hence to the plasma.
  • the frequency difference between the frequencies of oscillator network 202 and output network should be between 0.1 MHZ and 2 MHZ.
  • the frequency difference drops from about 1 MHZ for plasma without sample injection to about 0.4 MHZ as a sample is injected into the plasma.
  • the frequency of network 206 may even approach the same value as for oscillator 202 with certain sample introductions but may not be a lesser frequency due to instability.
  • the flow pattern and composition is changed, causing unfavorable conditions for sustaining the plasma, and the reactive coupling coefficient of the coil 14 is thereby altered to increase its apparent inductance. This decreases the resonant frequency of the output network to a value that is closer to the frequency of the oscillator, thereby coupling more power to the output network and hence stabilizing the plasma.
  • the level of power dissipated by the plasma is a function of the coupling coefficient of the load coil to the plasma which is sample dependent, while the power delivered to the plasma for a given sample condition is tightly regulated by the high voltage plate regulation of power triode 203 .
  • the plate voltage of power triode 203 will determine the RF output power delivered to the plasma.
  • the operating power is held constant throughout the changes in coupling between the coil and the plasma.
  • this is accomplished by means of a feedback network involving sampling the DC plate voltage and varying the fractional size of each of the applied half cycles of AC power supplied to the high voltage transformer primary.
  • This phase control (duty cycle) regulation allows the plate voltage to be adjustable from a few hundred volts to 4.5 KV DC and to be held constant over large line voltage transitions. With the plate voltage set to 3 KV and 75% of max loading, the regulation for the system described hereinbelow was found to be better than 1% when the line voltage was varied from 190 VAC to 256 VAC.
  • phase control regulator The operation of the phase control regulator can be seen with the aid of block diagram Fig. 3 and the wave forms shown in Fig. 4.
  • An accurately controlled DC voltage is provided by a control voltage source 208 and fed through line 252 to a summing circuit 210 .
  • a feedback signal proportional to the plate voltage of triode 203 enters circuit 210 where it is summed with the control voltage to generate an error voltage.
  • the error voltage is applied through line 254 , a control limit network 212 and line 256 to a voltage control current source 214 which provides a constant source of current proportional to the error voltage.
  • the current from line 258 charges a timing capacitor 216 , which charges linearly as shown in Fig. 4b, because of the constant current supply, at a rate that is determined by the magnitude of the current and, therefore, by the error voltage.
  • the voltage on timing capacitor 216 is sensed on line 260 by a voltage comparator 218 .
  • a synchronizing reference 224 is driven by the start of each half cycle of line voltage source 226 obtained through line 262 , a non-filtering full wave rectifier 228 and line 264 .
  • Reference 224 generates zero-crossing pulses synchronized by the line voltage. These pulses, indicated in Fig. 4a, are fed through line 266 to pulse trap 222 , which is reset by each pulse.
  • the comparator When the input voltage to voltage comparator 218 reaches a predetermined voltage, the comparator discharges timing capacitor 216 into a pulse driver 220 , via line 268 , which provides a trigger pulse (Fig. 4d) on its output line 272 .
  • the discharge of comparator 218 also fires, via line 270 , a pulse trap 222 which has been reset earlier in the cycle by the zero crossing pulses from line 266 .
  • the output of pulse trap 222 on line 268 is in the form of a square pulse (Fig. 4b) having a duration extending from the zero crossing (reset) to a time in the cycle established by the discharge timer 216 through voltage comparator 218 .
  • timing capacitor 216 The initial firing of pulse trap 222 unleashes voltage comparator 218 to allow timing capacitor 216 to start its charging cycle (Fig. 4c). By allowing timing capacitor 216 to always start its timing cycle referenced to the zero-crossing synchronized pulse, the regulator will always be in synchronization with the line.
  • the pulse driver 220 drives a 1:1:1 pulse transformer T1 which determines the firing angle of each of a parallel pair of silicon control rectifiers SCR1, SCR2.
  • These control rectifiers SCR1, SCR2 are in series with the AC power source to the DC power supply, as will be described below.
  • the firing angle and, therefore, the duty cycle (Fig. 4e) of these control rectifiers determine the AC voltage input to the high voltage DC power supply and, therefore, the DC voltage applied to oscillator circuit 202 (Fig. 2).
  • the duty cycle is established inversely to the plate voltage of triode 203 , any potential change initiated, for example, by a change in the plasma torch load or in the AC power supply, is caused to be nullified by inverse change in the duty cycling provided by the control rectifiers.
  • a feedback signal proportional to the plate voltage of triode 203 enters summing circuit 210 at connection I and is summed with a control voltage of -9.0 volts by operational amplifier U1 to generate an error voltage.
  • the response speed of the phase control regulator is determined by this amplifier; desirably its gain is 34 db with a breakpoint of 2 Hz with the gain decreasing 20 db/decade and reaching 0 db at 50 Hz.
  • the error voltage from U1 is supplied through control limit network 212 comprising resistors R13, R14 and zener diode CR15 to voltage controlled current source 214 comprising transistor Q3.
  • a timing capacitor 216 is charged linearly by Q3 output because of the constant current supply.
  • timing capacitor 216 is sensed via connection J by voltage comparator 218 comprising Q4, Fig. 6, which is a programable unijunction transistor.
  • Q4 fires and discharges capacitor 216 (from connection J) through resistor R31 into the base of pulse driver 220 comprising transistor Q5.
  • the pulse generated by Q4 also fires pulse trap 222 comprising control rectifier CR8 which, through resistor R17, clamps the gate of Q4 to 0.7V and prevents it from refiring and also prevents timer 216 from recharging.
  • Pulses to timing capacitor Q4 are synchronized with a synchronizing reference 224 (Fig. 6) comprising a buffer field effect transistor Q6 and zener diode CR11.
  • a line voltage 226 is rectified by a full wave rectifier 228 and fed to the gate of Q6 which, in conjunction with diode CR11, produces zero-crossing pulses (Fig. 4a) of one each half cycle. That buffered signal is limited to 3.9 volts through diode CR11 producing a very clipped pulse with spikes going to ground during zero crossing transients.
  • the zero-crossing sync pulse resets pulse trap CR8 and unlatches Q4 which allows capacitor 216 to start its charging cycle.
  • the upper and lower control limit circuit 212 (Fig. 5) which comprises resistors R13, R14, and diode CR15 is used to insure that when the regulator is set to the minimum DC output voltage SCR1 and SCR2 fire every half cycle to prevent an imbalance in the transformer; or, when set to maximum DC voltage, that the SCR's are not turned off prematurely due to the small voltage to current phase shift caused by the inductance of the transformer.
  • the maximum inductive phase shift is 14.4 o and the minimum delay limit is 27 o , the maximum delay limit is 162 o .
  • Resistor R8 to U1 in circuit 210 is used to keep the error voltage high, and Q3 at minimum charging current, to initialize a starting point when both the high voltage and the control voltage are off.
  • the pulse driver, Q5 drives pulse transformer T1 which triggers silicon control rectifiers SCR1, SCR2. These are rated at 35 amperes continuous at 800V peak.
  • a high DC voltage supply 230 takes 4,000 volts AC off of the secondary winding high voltage transformer T2 to a full wave rectifier bridge PF6.
  • the network includes a large external capacitor CR of 6 microfarads.
  • Metering resistors R1, R2, R3 include a voltage divider for suitable level of feedback voltage.
  • the plate voltage of tube 203 (Fig. 2) is supplied via connection H through choke T3.
  • the feedback voltage of about 0.4 volts is taken between resistor R1 and diode D1 and fed through connection I to the summing circuit 210 (Fig. 5).
  • the maintenance of a constant power level to the plasma for the duration of each run with a specific test sample is especially desirable while the sample substance is being injection into the plasma.
  • the power level may be different for different samples.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Electromagnetism (AREA)
  • Plasma Technology (AREA)

Claims (9)

  1. Ein ein Induktionsplasma erzeugendes System mit einem Plasmabrenner (10), einem Seistungs-LC-Oszillatornetzwerk (200), das auf eine erste resonante Radiofrequenz abgestimmt ist, einer induktiven Plasmaenergiezuführungsvorrichtung, die mit dem Plasmabrenner (10) zusammenwirkt, um darin induktiv eine kontinuierliche Plasmaentladung mit Energie zu versorgen, und einer Vorrichtung (Cc) zum Koppeln des Leistungs-LC-Oszillatornetzwerks (200) und der induktiven Plasmaenergiezuführungsvorrichtung, um einen Teil einer Radiofrequenzleistung von dem Leistungs-LC-Oszillatornetzwerk (200) an die induktive Plasmaenergiezuführungsvorrichtung und dadurch an die Plasmaentladung zu übertragen, dadurch gekennzeichnet, daß die induktive Plasmaenergiezuführungsvorrichtung ein getrenntes Ausgangs-LC-Oszillatornetzwerk (206) umfaßt, das gleichzeitig auf eine zweite resonante Radiofrequenz abgestimmt ist, die höher als die erste resonante Radiofrequenz ist.
  2. Ein ein Induktionsplasma erzeugendes System nach Anspruch 1, wobei der Unterschied zwischen der ersten resonanten Radiofrequenz und der zweiten resonanten Radiofrequenz zwischen 0,1 MHz und 2 MHz beträgt.
  3. Ein ein Induktionsplasma erzeugendes System nach Anspruch 1, wobei die Vorrichtung (Cc) zum Koppeln des Leistungs-LC-Oszillatornetzwerks (200) und des Ausgangs-LC-Oszillatornetzwerks (206) eine kapazitive Kopplung umfaßt.
  4. Ein ein Induktionsplasma erzeugendes System nach Anspruch 1, wobei das Ausgangs-LC-Oszillatornetzwerk eine mit dem Plasmabrenner (10) zusammenwirkende Induktionsspule (14) umfaßt, um darin eine Plasmaentladung mit Energie zu versorgen.
  5. Ein ein Induktionsplasma erzeugendes System nach Anspruch 1, wobei das Ausgangs-LC-Oszillatornetzwerk (206) und die Plasmaentladung reaktiv gekoppelt sind mit einem Kopplungskoeffizienten, wodurch die zweite Frequenz bestimmt wird, und wobei der Plasmabrenner (10) ein Brennerteil (12), eine Vorrichtung (38) zum Durchlassen von Plasma bildendem Gas durch das Brennerteil und eine Vorrichtung zum Verändern des Plasma bildenden Gases umfaßt, um den Kopplungskoeffizienten und dadurch die zweite resonante Radiofrequenz zu verändern.
  6. Ein ein Induktionsplasma erzeugendes System nach Anspruch 5, wobei das Ausgangs-LC-Oszillatornetzwerk (206) eine mit dem Brennerteil (12) zusammenwirkende Induktionsspule (14) umfaßt, um darin die Plasmaentladung mit Energie zu versorgen, und wobei die Vorrichtung zum Verändern des Plasma bildenden Gases eine Vorrichtung (50, 52) zum Injizieren einer Probensubstanz in die Plasmaentladung umfaßt, um somit eine Verringerung in der zweiten Frequenz zu bewirken, wodurch der Teil der auf das Ausgangs-LC-Oszillatornetzwerk übertragenen Radiofrequenz erhöht wird.
  7. Ein ein Induktionsplasma erzeugendes System nach Anspruch 1 oder 6, das weiter eine Vorrichtung zum Aufrechterhalten einer konstanten Leistung an die Plasmaentladung in Abhängigkeit von Änderungen in der reaktiven Kopplung zwischen der Plasmaentladung und dem Ausgangs-LC-Oszillatornetzwerk umfaßt.
  8. Ein ein Induktionsplasma erzeugendes System nach Anspruch 7, wobei die Vorrichtung zum Aufrechterhalten einer konstanten Leistung umfaßt: einen Radiofrequenzgenerator, der die Induktionsspule und eine mit der Induktionsspule gekoppelte Leistungstriode (203) mit einer Platte enthält, eine Gleichspannungsleistungsversorgung (230), zum Bewirken einer gleichgerichteten Spannung an der Triodenplatte, die einen Eingangstransformator (T2) mit einer eine Wechselstromleistung empfangenden Primärwicklung enthält, einen die Netzspannung empfangenden Wechselstromschaltkreis zum Bewirken der Wechselstromleistung, der eine Vorrichtung zur Tastgradeinstellung der Wechselstromleistung in Abhängigkeit von einem Steuersignal enthält, eine Rückkopplungsvorrichtung (210, 254) zum Erzeugen eines Rückkopplungssignals in bezug auf die gleichgerichtete Spannung, und eine Steuervorrichtung für das Rückkopplungssignal zum Erzeugen eines Steuersignals derart, daß eine Änderung in der gleichgerichteten Spannung eine umgekehrte Änderung in der Tastgradeinstellung bewirkt, um somit die Änderung in der gleichgerichteten Spannung abzugleichen.
  9. Ein ein Induktionsplasma erzeugendes System nach Anspruch 8, wobei der Steuergleichrichter einen Siliziumsteuergleichrichter (SCR1, SCR2) mit einem der Tastgradeinstellung entsprechenden Feuerungswinkel umfaßt, und wobei die Steuervorrichtung eine Stromvorrichtung (214) zum Bewirken eines Timing-Stroms in Abhängigkeit von einem Rückkopplungssignal, einen Timing-Kondensator (216), der den Timing-Strom zum Aufladen des Timing-Kondensators (216) empfängt, eine die Wechselstromleistung empfangende synchronisierende Vorrichtung (224) zum Beginnen des Aufladens des Timing-Kondensators (216) bei einer vorbestimmten Phase des Wechselstromleistungszyklus, eine Komparatorvorrichtung (218) zum Entladen des Timing-Kondensators (216), um einen Entladungspuls zu erzeugen, wenn der Timing-Kondensator (216) eine vorbestimmte Spannung erreicht, und eine den Entladungspuls empfangende Vorrichtung (220) umfaßt, zum Bewirken von das Steuersignal aufbauenden Steuerpulsen, wobei der Feuerungswinkel von den Steuerpulsen abhängt.
EP88103403A 1987-03-06 1988-03-04 Energieversorgung für einen induktiv gekoppelten Plasmabrenner Expired - Lifetime EP0281157B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US22838 1987-03-06
US07/022,838 US4818916A (en) 1987-03-06 1987-03-06 Power system for inductively coupled plasma torch

Publications (3)

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EP0281157A2 EP0281157A2 (de) 1988-09-07
EP0281157A3 EP0281157A3 (en) 1990-03-28
EP0281157B1 true EP0281157B1 (de) 1994-06-29

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EP (1) EP0281157B1 (de)
JP (1) JP2708447B2 (de)
DE (1) DE3850422T2 (de)

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Publication number Priority date Publication date Assignee Title
JPH02215038A (ja) * 1989-02-15 1990-08-28 Hitachi Ltd マイクロ波プラズマ極微量元素分析装置
US5055743A (en) * 1989-05-02 1991-10-08 Spectra Physics, Inc. Induction heated cathode
US5047692A (en) * 1990-01-30 1991-09-10 General Electric Company Integrated tuning capacitor network and heat sink for an electrodeless high intensity discharge lamp ballast
US5155547A (en) * 1990-02-26 1992-10-13 Leco Corporation Power control circuit for inductively coupled plasma atomic emission spectroscopy
GB9226335D0 (en) * 1992-12-17 1993-02-10 Fisons Plc Inductively coupled plasma spectrometers and radio-frequency power supply therefor
US5383019A (en) * 1990-03-23 1995-01-17 Fisons Plc Inductively coupled plasma spectrometers and radio-frequency power supply therefor
KR930004713B1 (ko) * 1990-06-18 1993-06-03 삼성전자 주식회사 변조방식을 이용한 플라즈마 발생장치 및 방법
DE4021182A1 (de) * 1990-07-03 1992-01-16 Plasma Technik Ag Vorrichtung zur beschichtung der oberflaeche von gegenstaenden
US5095189A (en) * 1990-09-26 1992-03-10 General Electric Company Method for reducing plasma constriction by intermediate injection of hydrogen in RF plasma gun
US5159173A (en) * 1990-09-26 1992-10-27 General Electric Company Apparatus for reducing plasma constriction by intermediate injection of hydrogen in RF plasma gun
NO174180C (no) * 1991-12-12 1994-03-23 Kvaerner Eng Innföringsrör for brenner for kjemiske prosesser
US5216330A (en) * 1992-01-14 1993-06-01 Honeywell Inc. Ion beam gun
EP0792091B1 (de) * 1995-12-27 2002-03-13 Nippon Telegraph And Telephone Corporation Verfahren zur elementaren Analyse
ES2115542B1 (es) * 1996-07-24 1999-02-16 Iberdrola Sa Fuente de alimentacion de antorchas de hornos de plasma.
US6329757B1 (en) 1996-12-31 2001-12-11 The Perkin-Elmer Corporation High frequency transistor oscillator system
US5925266A (en) * 1997-10-15 1999-07-20 The Perkin-Elmer Corporation Mounting apparatus for induction coupled plasma torch
US6222186B1 (en) 1998-06-25 2001-04-24 Agilent Technologies, Inc. Power-modulated inductively coupled plasma spectrometry
EP1203441A1 (de) 1999-07-13 2002-05-08 Tokyo Electron Limited Hochfrequenz-stromquelle zur erzeugung eines induktiv gekoppelten plasmas
US7511246B2 (en) 2002-12-12 2009-03-31 Perkinelmer Las Inc. Induction device for generating a plasma
US7106438B2 (en) * 2002-12-12 2006-09-12 Perkinelmer Las, Inc. ICP-OES and ICP-MS induction current
US8057468B2 (en) 2002-12-17 2011-11-15 Bovie Medical Corporation Method to generate a plasma stream for performing electrosurgery
DE10345890A1 (de) * 2003-09-30 2005-04-28 Siemens Ag Verfahren und Vorrichtung zur Stabilisierung eines Verbrennungsvorganges
US7663319B2 (en) * 2004-02-22 2010-02-16 Zond, Inc. Methods and apparatus for generating strongly-ionized plasmas with ionizational instabilities
AU2012202363B2 (en) * 2005-03-11 2014-08-14 Perkinelmer U.S. Llc Plasmas and methods of using them
WO2006099190A2 (en) * 2005-03-11 2006-09-21 Perkinelmer, Inc. Plasmas and methods of using them
US8622735B2 (en) * 2005-06-17 2014-01-07 Perkinelmer Health Sciences, Inc. Boost devices and methods of using them
US7742167B2 (en) * 2005-06-17 2010-06-22 Perkinelmer Health Sciences, Inc. Optical emission device with boost device
US7459899B2 (en) 2005-11-21 2008-12-02 Thermo Fisher Scientific Inc. Inductively-coupled RF power source
US7863785B2 (en) * 2007-08-08 2011-01-04 Anadish Kumar Pal High power-density static-field ac conduction motor
JP2011522381A (ja) 2008-05-30 2011-07-28 コロラド ステート ユニバーシティ リサーチ ファンデーション プラズマに基づく化学源装置およびその使用方法
WO2009146439A1 (en) 2008-05-30 2009-12-03 Colorado State University Research Foundation System, method and apparatus for generating plasma
US8994270B2 (en) 2008-05-30 2015-03-31 Colorado State University Research Foundation System and methods for plasma application
US9649143B2 (en) * 2009-09-23 2017-05-16 Bovie Medical Corporation Electrosurgical system to generate a pulsed plasma stream and method thereof
US8222822B2 (en) 2009-10-27 2012-07-17 Tyco Healthcare Group Lp Inductively-coupled plasma device
US8795265B2 (en) 2010-01-28 2014-08-05 Bovie Medical Corporation Electrosurgical apparatus to generate a dual plasma stream and method thereof
CA2794902A1 (en) 2010-03-31 2011-10-06 Colorado State University Research Foundation Liquid-gas interface plasma device
CA2794895A1 (en) 2010-03-31 2011-10-06 Colorado State University Research Foundation Liquid-gas interface plasma device
CA2796819C (en) * 2010-05-05 2018-08-21 Perkinelmer Health Sciences, Inc. Oxidation resistant induction devices
US9387269B2 (en) 2011-01-28 2016-07-12 Bovie Medical Corporation Cold plasma jet hand sanitizer
US20160121418A1 (en) * 2012-01-25 2016-05-05 Gordon Hanka Welder Powered Arc Starter
EP2904881B1 (de) 2012-07-13 2020-11-11 PerkinElmer Health Sciences, Inc. Brenner mit miteinander gekoppelten feuerfesten und nicht-feuerfesten materialien
GB2508824A (en) * 2012-12-11 2014-06-18 Linde Ag Piezoelectric apparatus for generating voltage from a compressed gas
US9532826B2 (en) 2013-03-06 2017-01-03 Covidien Lp System and method for sinus surgery
US9555145B2 (en) 2013-03-13 2017-01-31 Covidien Lp System and method for biofilm remediation
EP2984908B1 (de) * 2013-04-08 2022-02-09 PerkinElmer Health Sciences, Inc. Kapazitiv gekoppelte vorrichtungen
US9635750B2 (en) 2013-10-23 2017-04-25 Perkinelmer Health Sciences, Inc. Oscillator generators and methods of using them
CN206237661U (zh) * 2013-10-23 2017-06-09 珀金埃尔默健康科学股份有限公司 混合式发生器、包括其的系统、质谱仪和化学反应器
WO2017096112A1 (en) 2015-12-02 2017-06-08 Bovie Medical Corporation Mixing cold plasma beam jets with atmosphere
AU2017257870B2 (en) * 2016-04-27 2022-12-01 Perkinelmer U.S. Llc Oscillator generators and methods of using them
US10918433B2 (en) 2016-09-27 2021-02-16 Apyx Medical Corporation Devices, systems and methods for enhancing physiological effectiveness of medical cold plasma discharges
NL2018778B1 (en) 2017-04-25 2018-11-05 Skil B V Power tool
CN107634587B (zh) * 2017-09-20 2024-06-11 扬州芯智瑞电子科技有限公司 一种基于特斯拉线圈的改良型无线供电系统
US10798809B2 (en) * 2018-07-13 2020-10-06 Shimadzu Coporation Inductively coupled plasma generator

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3467471A (en) * 1963-10-21 1969-09-16 Albright & Wilson Mfg Ltd Plasma light source for spectroscopic investigation
US3958883A (en) * 1974-07-10 1976-05-25 Baird-Atomic, Inc. Radio frequency induced plasma excitation of optical emission spectroscopic samples
US4225769A (en) * 1977-09-26 1980-09-30 Thermal Dynamics Corporation Plasma torch starting circuit
ZA841218B (en) * 1983-03-08 1984-09-26 Allied Corp Plasma excitation system

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EP0281157A2 (de) 1988-09-07
US4818916A (en) 1989-04-04
JPS63304598A (ja) 1988-12-12
JP2708447B2 (ja) 1998-02-04
EP0281157A3 (en) 1990-03-28
DE3850422T2 (de) 1994-11-10
DE3850422D1 (de) 1994-08-04

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